JPH10151709A - Biaxially stretched film made of cyclic olefin polymer, its use and production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a biaxially stretched film from a cyclic olefin polymer having especially good slip characteristics and electrical properties and a method for using and producing the same. SOLUTION: A film having one or more layer and having a base layer made of a cyclic olefin polymer and at least one outer layer is produced. The base layer is substantially formed of a cyclic olefin polymer COP having glass transistion temp. Tg and the outer layer is substantially formed of a mixture of cyclic olefin polymers. A mixture of cyclic olefin polymers contains at least two kinds of cyclic olefin polymers COP1 , COP2 and the glass transition temps. Tg1 , Tg2 of these two kinds of polymers are different at least by 5 deg.C and, in this case, Tg2 -T1 >=5 deg.C is set and, at the same time, a condition Tg2 -Tg>=5 deg.C is satisfied.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a film having one or more layers and made of a cyclic olefin polymer and having a base layer and at least one outer layer, said base layer having a glass transition temperature Tg. And the outer layer is substantially made from a mixture of cyclic olefin polymers. The present invention also relates to the use of the film and a method for producing the film. The novel films of the present invention are distinguished by improved processing performance and electrical properties. The film is excellent for use as a capacitor dielectric.

[0002]

BACKGROUND OF THE INVENTION Cyclic olefin polymers are known materials that are distinguished by high heat resistance, high modulus, low water absorption and good dielectric properties. Films made from cyclic olefin polymers are likewise known in the prior art.

[0003] DD-A-224 538 describes the production of films from norbornene ethylene copolymers by the film casting method. European Patent Application EP-A
-0384 694, EP-A-0 610 814, E
P-A-0 610 815 and EP-A-0 610 8
No. 16 describes the production of a cyclic olefin polymer film by a melt extrusion method. Mechanical properties are improved by uniaxially or biaxially stretching the film.

[0004] DD-241 971 and DD-224 5
38 states that films made from cyclic olefin polymers are distinguished by a small dielectric loss tangent (tan δ). The tan δ for the COC film is 1.
It is stated that it can be less than ^{2.10 -5} . Further, particular interest for high frequency AC applications of the film is described in DD-241 971, since low values of tan δ prevent power loss and temperature rise in the film.

[0005] EP-A-0 384 694 describes that cyclic olefin polymers can be stretched uniaxially and biaxially to give stretched films. The patent application states that prior to stretching, the polymers must be heated to a temperature above their glass transition temperature. Additives such as, for example, antiblocking agents can be added to the film to prevent sticking that occurs during further processing. The patent application does not mention the electrical properties of films made from cyclic olefin polymers.

[0006] EP-A-0 610 814, EP-A-
0 610 815 and EP-A-0610 816
It relates to films having one or more layers and made from cyclic olefin copolymers (COCs) and to their use as capacitor dielectrics. Less than the glass transition temperature of COC 4
Uniaxial or biaxial stretching in the temperature range from 0 ° C. to 50 ° C. above this temperature is described. It has been recommended that fine inert particles be incorporated into the film to improve the ease of further processing of the film and to improve the sliding and winding characteristics of the film. Examples of the inert particles _{described, SiO 2, Al 2 O 3} , silicates, carbonates, sulfides, cited polytetrafluoroethylene, talc, lithium fluoride, and various salts of organic acids.

Known films made from cyclic olefin polymers are unsatisfactory with regard to the ease of further processing of said films, in particular with regard to the sliding and winding properties of said films. Further, there is a need for good electrical properties such as, for example, a low dielectric loss tangent and a high breakdown voltage. These advantages may not be impaired by improving the sliding and winding properties.

When using known non-polymeric organic and / or inorganic antiblocking agents, the particles do not adhere well to the cyclic olefin polymer matrix. Furthermore, there is a risk that voids (vacuum) may be formed during stretching. Both of these phenomena cause extremely undesirable degradation of the electrical properties of the film.

[0009] In the most frequently encountered areas of application, capacitor films are metallized. Unfortunately, these additives often cause problems when metallizing the film surface. The metal layer does not adhere well to the protruding particles and becomes incomplete when the antiblocking agent causes the particles to lose adhesion. Poor metal adhesion and metal layer defects are especially problematic in capacitor films. As a result, in particular, the loss tangent decreases,
The film can no longer be used for its intended use.

[0010]

SUMMARY OF THE INVENTION An object of the present invention was to prevent the above-mentioned disadvantages of known films. In particular, a cyclic olefin polymer film having good sliding and electrical properties should be provided. The film is
It should be easy to process, have low friction, and not stick. However, the suitability of the film as a capacitor film must not be impaired by improving the slip properties. Therefore, the film
In particular, it must have a small dielectric loss tangent.

The object of the invention has been achieved by a film of the type mentioned at the outset. A characteristic of the film is that the cyclic olefin polymer mixture of the outer layer comprises at least two cyclic olefin polymers COP ₁ and COP ₂ . Glass transition temperature T of the two polymers
g ₁ and Tg ₂ differ by at least 5 ° C., where Tg ₂
−Tg ₁ ≧ 5 ° C. At the same time, the condition Tg ₂ −Tg ≧ 5 ° C. is satisfied.

The base layer of the novel film is made from a cyclic olefin polymer or a mixture of cyclic olefin polymers. The base layer generally contains from 90 to 100% by weight of the cyclic olefin polymer or mixture and, if desired, an effective amount of conventional additives. The base layer comprises a cyclic olefin polymer or mixture, preferably 95-99% by weight, in particular 98-99% by weight.
Contains 99% by weight. The weight percentages of the units of data are based on the weight of the substrate.

For the purposes of the present invention, cyclic olefin polymers are homopolymers or copolymers containing polymerized cyclic olefin units and, if desired, acyclic olefins as comonomers. Suitable cyclic olefin polymers for the present invention comprise, in each case 0.1 to 100% by weight, preferably 10 to 99% by weight, of polymerized cyclic olefin units, based on the total weight of the cyclic olefin polymer.
% By weight, especially 50 to 95% by weight. Preferably, the following formulas I, II, III, IV, V or VI:

Embedded image (Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and R
⁸ is the same or different and is a hydrogen atom or C ₁ -C ₃₀
-Is a hydrocarbon group or in the formula two or more groups R ¹
To R ⁸ it is not coupled to the ring, also in the formula the meanings of the same group is a polymer made from a cyclic olefin represented by may be different in different formulas). C ₁ -C
Examples of ₃₀ -hydrocarbon groups include linear or branched C ₁ -C
₈ - alkyl group, C ₆ -C ₁₈ - aryl groups, C ₇ -C ₂₀ - alkylene aryl group, a cyclic C ₃ -C ₂₀ - alkyl groups and acyclic C ₂ -C ₂₀ - include alkyl groups.

If desired, the cyclic olefin polymer may be
Based on the total weight of the cyclic olefin polymer, the following formula VII:

Embedded image (N is a number of 2 to 10) and may contain 0 to 45% by weight of a polymerized unit of at least one kind of monocyclic olefin.

If desired, the cyclic olefin polymer may be
Based on the total weight of the cyclic olefin polymer, the following formula VIII:

Embedded image (R ⁹ , R ¹⁰ , R ¹¹ and R ¹² may be the same or different and represent a hydrogen atom or a C ₁ -C ₁₀ -hydrocarbon group, for example C _1-
C ₈ - alkyl group or a C ₆ -C ₁₄ - polymerized units of an acyclic olefin may contain 0-99% by weight represented by the aryl is group).

Cyclic olefin polymers obtained by ring-opening polymerization of at least one of the monomers of the formulas I to VI and subsequent hydrogenation are equally suitable.

The cyclic olefin homopolymers have the formulas IV
Made from one monomer of I. For the present invention,
Preferred are cyclic olefin copolymers comprising at least one cyclic olefin of formulas I-VI and an acyclic olefin of formula VIII as a comonomer. Preferred acyclic olefins according to the invention are those having 2 to 20 carbon atoms, in particular unbranched acyclic olefins having 2 to 10 carbon atoms such as, for example, ethylene, propylene and / or butylene. It is a formula olefin. The proportion of the polymerized unit of the acyclic olefin represented by the formula VIII is 99% by weight or less, preferably 5 to 80% by weight, particularly preferably 10 to 80% by weight, based on the total weight of each cyclic olefin polymer. ６０60% by weight.

Preferred cyclic olefin polymers among the above cyclic olefin polymers are those containing polymerized units of a polycyclic olefin based on a norbornene structure, particularly preferably norbornene or tetracyclododecene. Also preferred are acyclic olefins, especially cyclic olefin copolymers containing polymerized units of ethylene. Particularly preferred are norbornene ethylene and tetracyclododecene ethylene copolymers containing from 5 to 80% by weight, preferably from 10 to 60% by weight (based on the weight of the copolymer) of ethylene.

The above-mentioned cyclic olefin polymer generally has a glass transition temperature Tg of -20 ° C to 400 ° C, preferably 50 ° C to 200 ° C. Viscosity number (decalin, 135
C, DIN 53728) is generally 0.1-200 m
l / g, preferably 50-150 ml / g.

The preparation of these cyclic olefin polymers is carried out using a homogeneous or heterogeneous catalytic reaction with an organometallic compound. Suitable catalyst systems based on mixed catalysts made from titanium compounds and / or vanadium compounds in combination with organoaluminum compounds are described in DD 109 224, DD 237 070 and E
PA-0283164. EP-A
−0 283 164, EP-A-0 407 870, E
PA-485 893 and EP-A-0 503422
Describes the preparation of cyclic olefin polymers using catalysts based on suitable metallocene complexes. The method of preparing the cyclic olefin polymer described in said patent application is specifically incorporated herein by reference.

The novel film of the present invention has at least one outer layer in addition to the above-mentioned base layer, and preferably has outer layers on both sides. This outer layer or layers are also substantially made from the cyclic olefin polymer described above for the base layer. It is important for the purposes of the present invention that the outer layer comprises at least two different cyclic olefin polymers COP ₁ and COP ₂ which are selected from the cyclic olefin polymers mentioned above for the base layer and whose glass transition temperature differs. . The difference between the glass transition temperatures Tg ₁ and Tg ₂ is at least 5 ° C., preferably at least 10-15.
0 ° C., especially 20-100 ° C., and Tg ₂ > Tg ₁
It is.

The higher glass transition temperature Tg of COP _2
2 is a further advantageous if above the glass transition temperature Tg of the base layer of the cyclic olefin polymer, preferably a difference of at least 5 ° C., particularly preferably at least 10 to 150
° C., in particular 20 to 100 ° C., preferably a Tg _2> Tg.

Surprisingly, the addition of a cyclic olefin polymer COP ₂ having a higher glass transition temperature Tg ₂ in the outer layer (s) can create a rough surface when the film is stretched. Was found. The surface roughness of the film can be precisely tuned and adapted to any particular requirements by changing the type and amount of the cyclic olefin polymer COP ₂ having a higher glass transition temperature. By this measure, it is possible to dispense with the use of the conventional granular antiblocking agent. The new morphology is easier to metallize and process than comparable films with particulate antiblocking agents. CO added
Although P ₂ does not produce separated particles in the outer layer, surprisingly, nevertheless a rough film surface results. Unexpectedly, the rough surface of the new film is distinguished by a particularly homogeneous surface roughness.

Furthermore, the observed dielectric loss tangent is much lower than that of films made from cyclic olefin polymers with conventional particulate antiblocking agents.

The outer layer generally has a total of at least 90 to 100 in each case, based on the weight of the outer layer.
% By weight, preferably 95-99% by weight, especially 98-99%
% By weight. The data relate to the total content of cyclic olefin polymers (COP ₂ and COP ₁ ).
If desired, effective amounts of conventional additives may also be present in the outer layer.

The outer layer is generally, based on the weight of the outer layer in each case, a cyclic olefin polymer COP ₂ having a high glass transition temperature Tg _2, 0.5 to 25 wt%, preferably 2 to 15 % By weight, especially 5 to 10% by weight. The proportion of cyclic olefin polymer COP ₁ having Tg ₁ is in each case 9%, based on the weight of the outer layer.
It is 9.5 to 75% by weight or less, preferably 98 to 85% by weight, particularly 95 to 90% by weight.

The outer layer mixture of COP ₁ and COP ₂ may be prepared by any of the commonly known methods such as, for example, mechanical mixing of powders or granules, or extrusion mixing followed by crushing.

As mentioned above, the individual layers of the film
In addition to the cyclic olefin polymer, it may also contain an effective amount of a suitable additive. In principle, any additives customarily used in polyolefin films, such as, for example, polyethylene films or polypropylene films, are suitable. The incorporation of the outer layer according to the present invention eliminates the use of known conventional antiblocking agents. The use of lubricants and antistatic agents commonly used in packaging films should be avoided in capacitor applications. The reason is that these additives impair the electrical properties. Therefore, regarding the condenser film,
Stabilizers, neutralizers and antioxidants are preferred.

Preferred neutralizing agents have an average particle size of less than 0.7 μm, an absolute particle size of less than 10 μm, and at least 40 m ^2.
/ g dihydrotalcite, calcium stearate and / or calcium carbonate. Neutralizing agents are generally added in amounts of 0.02 to 0.1% by weight.

Examples of UV stabilizers are absorbers such as, for example, hydroxyphenylbenzotriazole, hydroxybenzophenone, formamidine or benzylidene camphor, quenchers such as cinnamate or nickel chelates, for example sterically hindered phenols Free radical scavengers such as, for example, hydroperoxide decomposers such as nickel or zinc complexes of sulfur-containing compounds, HALS type light stabilizers or mixtures thereof.

Stabilizers that can be used are ethylene,
It is a common stabilizing compound for polymers of propylene and other olefins. They are 0.05-2% by weight
Add in amounts. Phenolic stabilizer, alkali metal / alkaline earth metal stearate and / or alkali metal /
Alkaline earth metal carbonates are particularly suitable. 0.1
Preference is given to phenolic stabilizers having a molar mass of more than 500 g / mol, used in an amount of from .about.0.6% by weight, in particular from 0.15 to 0.4% by weight. Pentaerythritol tetrakis-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate or 1,3,5-trimethyl-
2,4,6-Tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene is particularly preferred.

Examples of antioxidants which can be used are free-radical scavengers, for example substituted phenols and aromatic amines, and / or peroxide decomposers, for example phosphites, phosphates and thio compounds. is there.

The total thickness of the new film is generally between 2 and 50
μm, preferably 3 to 30 μm. The base layer is the layer that makes up at least 50% of the total thickness of the film.
The thickness of the outer layer (s) is 0.1-5 μm, preferably 0.5-3 μm, especially 0.5-1 μm. Preferred embodiments have outer layers on both sides, which may have the same or different structures. A three-layer film having the same outer layer, ie, a film having a symmetric structure, is preferred.

The present invention further provides a method for producing a novel film. Preferably, the production is carried out by extrusion methods known per se or by coextrusion methods, in a customary manner known to the person skilled in the art.

In this method, usually, in coextrusion,
In the extruder, the polymer or polymer mixture of the individual layers is compressed, melted and liquefied; if desired, additives which may be added may already be present in the polymer or polymer mixture. Alternatively, it may be added using a master batch method. Preferably, the polymer mixture for the outer layer is prepared in a separate step. Also, if desired, the ingredients for the outer layer can be mixed in the extruder. Next, the melts corresponding to the individual layers of the film are co-extruded together and simultaneously through a flat film extrusion die, and the extruded film having one or more layers is taken up by one or more take-off rolls. In the meantime, it cools and solidifies. The temperature of the take-off roll is generally between 20 and 180C, preferably between 60 and 130C.

Next, the obtained film is stretched parallel to and perpendicular to the extrusion direction to give an orientation to the molecular chains. The stretching ratio in the machine direction is preferably 1.1: 1 to 1.
4: 1, and the stretching ratio in the transverse direction is preferably 2: 1 to 5: 1. The longitudinal stretching is conveniently effected with the aid of two rolls running at different speeds corresponding to the desired stretching ratio, and the transverse stretching is effected on a suitable tentering machine. However, in principle, the film can also be stretched using other known stretching methods.

Usually, after biaxial stretching, heat setting (heat treatment) is performed, and finally the film is wound. To increase surface tension, one or both sides of the film may be corona treated or flame treated, if desired, after biaxial stretching, by one of the known methods.

The temperature at which the films are stretched in the machine and / or transverse directions should be adapted to the particular cyclic olefin polymer grade used, and in particular their glass transition temperature. Both longitudinal stretching temperature T _l and transverse stretching temperature T _q is dependent on the formulation of the base layer, also depends on the Tg ₂ of Tg ₁ and COP ₂ of COP ₁ of the outer layer.

[0039] T both of _l and T _q is, the base layer of the COP Tg
And the Tg ₁ of the COP ₁ of the outer layer must exceed at least 5 ° C., preferably 10 to 150 ° C. In the case of a COP mixture in the base layer, the polymer mixture in the base layer that can be stretched must be heated sufficiently.
In that case, the stretching temperature generally depends on the main component having the highest Tg in the base layer.

[0040] In order to achieve the required surface roughness of the film, when determining the stretching temperature T _l and T _q, should be further considered the glass transition temperature of COP ₂ used in the outer layer.
Stretching temperature (i.e., T _l is normal) of first performing the stretching step is at least 3 ° C. than the glass transition temperature Tg ₂ of COP _2, should preferably be at least 5 ° C. lower. In principle, T _q may be independently selected with respect to Tg _2, may be less than or greater than Tg _2. However, at the same time, as described above, the stretching temperature herein should be considered so exceeds the Tg and Tg ₁ of other cyclic olefin polymer. Satisfying these conditions should impart good orientability and desired surface roughness to the film without the use of additional antiblocking agents.

Presumably, mixing in the outer layer (s) of the cyclic olefin polymer COP ₂ with a high glass transition temperature Tg ₂ breaks the surface layer during the drawing process,
Gives a rough surface without forming separated particles of ₂ . Surprisingly, the surface roughness can be adjusted over a wide range of the invention by varying the type and amount of cyclic olefin polymer used in the outer layer (s); A better sliding friction value and a dielectric loss tangent can be obtained as compared with the case where an agent is used.

The novel films may be metallized using conventional methods known to those skilled in the art. The metal layer applied to at least one surface layer of the film during metallization may consist of any suitable metal. Preferably a layer of aluminum, zinc, gold or silver or a suitable alloy, particularly preferably aluminum or an aluminum-containing alloy. Suitable metallization methods are electroplating, sputtering and vacuum deposition, preferably vacuum deposition. The thickness of the metal layer is about 20-600 nm, preferably 25-100 nm.

Prior to metallization, if desired, the film may be surface treated with a flame or corona. However, it is also possible to provide the novel film with a metal layer without taking the conventional measures to increase the surface energy. An advantage of this embodiment is that the cyclic olefin polymer film can be metallized on both sides as well as on one side. Capacitors may be manufactured from metallized cyclic olefin polymer films in a conventional manner.

Hereinafter, the present invention will be described in more detail with reference to examples.

Example 1 (COP ₁ having a Tg of 140 ° C.)
And / or Preparation of COP) In a 1.5 dm ³ flask, a petroleum fraction (boiling point range 90-1)
10 liters) and 20 ml of a methylaluminoxane solution in toluene (1300 as measured by freezing point depression method).
9. Methylaluminoxane having a molar mass of g / mol.
1% by weight) and stirred at 70 ° C. for about 30 minutes to remove any contaminants present. After draining the solution,
The reactor was charged with 480 cm ^{3 of an} 85% by weight solution of norbornene in toluene. The solution is saturated with ethylene by repeatedly pressurizing with ethylene (6 bar G), then 10 cm ³ of a toluene solution of methylaluminoxane are added to the reactor and the mixture is added to 70
Stirred at C for 5 minutes. After 15 minutes of preactivation, a 5.43 mg solution of isopropylene- (1-cyclopentadienyl) (1-indenyl) -zirconium dichloride in 10 cm ^{3 of a} methylaluminoxane solution in toluene was added. The mixture was stirred at 70 ° C. for 30 minutes (750 rpm /
Minutes) and polymerize, then meter in ethylene and inject,
The ethylene pressure was kept at 18 barG. The homogeneous reaction solution was drained into a vessel and mixed with about 1 ml of water. The solution was then mixed with a filter aid and filtered through a pressure filter. The resulting solution is quickly poured into 5 dm ^{3 of} acetone,
Stirred for 10 minutes and filtered. The obtained solid was washed with acetone. Again, the polymer was filtered off at 80 ° C. and 0.2
Dry at bar pressure for 15 hours.

89.1 g of a colorless polymer was obtained. To determine the viscosity number, 0.1 g of the resulting polymer was dissolved in 100 ml of decalin and measured at 135 ° C. on the solution in a capillary viscometer. The viscosity number is 56.5dl / g
Met. Glass transition temperatures were measured using a Perkin Elmer DSC7. From the second heating curve at a heating rate of 20 ° C./min, the glass transition temperature was 140 ° C. ^The ethylene content, measured using ¹³ C nuclear magnetic resonance spectroscopy, is 49.
Mole%. The molecular weight of the polymer was measured at 135 ° C. using gel permeation chromatography in ortho-dichlorobenzene. The polyethylene fraction was used as a reference. The following values were found for the resulting polymer: M
n: 21,500 g / mol; M _W : 45,000 g / mol; M
_{W /} Mn: 2.1.

Example 2 (COP ₂ having a Tg of 165 ° C.)
Preparation of Polymer) A polymer was prepared by the method described in Example 1. The ethylene pressure was set at 5 bar G and 4.78 mg of isopropylene- (9-fluorenyl) cyclopentadienylzirconium dichloride was used as catalyst. After isolating the polymer, the following amounts and properties were found: Yield: 56 g; solution viscosity: 81 ml / g; glass transition temperature 1
63 ° C .; ethylene content: 45 mol%; molecular weight; Mn: 4
3,900g / mol; M _W: 83,800g / mol; M _W / M
n: 1.9.

Example 3 (Preparation of a mixture of COP ₁ and COP ₂ ) A mixture of 16 kg of COP ₁ and 4 kg of COP ₂
At a melting temperature of 0 ° C., the mixture was extruded on a twin screw extruder and the cured extrudate was then crushed. 19.2 kg of colorless and cloudy granules were obtained. According to DSC, 13
A glass transition temperature of 9 ° C (Tg ₁ ) and another weaker glass transition temperature of 164 ° C (Tg ₂ ) were obtained.

Example 4 (Preparation of a mixture of COP ₁ and Syloblock 44) A mixture of 16 kg of COP ₁ and 4 kg of Syloblock 44 was
At a melt temperature of 240 ° C., the mixture was extruded on a twin screw extruder and the cured extrudate was then crushed. 19.3 kg of colorless and cloudy granules were obtained. According to DSC,
A glass transition temperature of 139 ° C. (Tg ₁ ) was obtained.

Examples 5, 6, 7 A three-layer film having an ABA layer structure, that is to say that the base layer B is surrounded by two identical outer layers A, was subjected to a twin-screw extrusion followed by longitudinal and transverse stretching. Manufactured by step stretching.

Substrate B consisted essentially of COP _{1 as} described in Example 1 and contained 0.2% by weight of a phenolic stabilizer. Each of the two outer layers is substantially
98% by weight (based on the total weight of the cyclic olefin copolymer in the individual outer layers) of the COP ₁ from Example ₁
2% by weight of COP ₂ from Example 2 and 0.1% (based on the total weight of the outer layer).
2% by weight consisted of the phenolic stabilizer.

Each layer of the film was extruded together through a flat film die at an extrusion temperature of 230 ° C. and a die temperature of 240 ° C. 90 ° C.
At a take-up roll and then at a temperature of 15 before winding.
Stretching in the machine direction at 0 to 160 ° C (machine direction stretching ratio: 2.
0), and then stretched in the transverse direction at a temperature of 170 to 175 ° C (transverse stretching ratio: 3.2).

Table 1 shows properties measured for the film thus manufactured. The film had no tendency to stick and had good winding behavior.

COMPARATIVE EXAMPLES 8 AND 9 A three-layer film having an ABA layer structure, ie, a base layer B surrounded by two identical outer layers A, was subjected to a twin-screw extrusion and subsequent longitudinal and transverse steps. Manufactured by stretching.

Substrate B consisted essentially of COP _{1 as} described in Example 1 and contained 0.2% by weight of a phenolic stabilizer. Similarly, the two outer layers correspond to the C of Example 1.
It consisted essentially of OP ₁ and 0.2% by weight of a phenolic stabilizer.

As described in Examples 5 to 7, first, the base layer and the outer layer were heated at an extrusion temperature of 230 ° C. and a temperature of 240 ° C.
At a die temperature of 90 ° C., and then stretched longitudinally at a temperature of 150 to 160 ° C. (winding ratio: 2.0) before winding, and then at a temperature of 170 ° C. before winding. ~ 17
The film was stretched in the transverse direction at 5 ° C (transverse stretching ratio: 3.2).

Table 1 shows properties measured for the film thus manufactured. The film could not be wound without wrinkling because of the high mutual friction.

Comparative Examples 10 and 11 (Preparation of a biaxially stretched film from COP ₁ and Syloblock 44 as an additive in the outer layer) having an ABA layer structure, ie a base layer B
A three-layer film surrounded by two identical outer layers A was produced by twin-screw extrusion followed by step stretching in the machine and transverse directions.

Substrate B consisted essentially of COP _{1 as} described in Example 1 and contained 0.2% by weight of a phenolic stabilizer. Each of the two outer layers is substantially
(Cyclic olefin copolymer COP in each outer layer
99.6% by weight (based on the total weight of ₁ ) consisted of COP ₁ from Example 1 and 0.4% by weight Sylobloc
k 44 and 0.2% by weight (based on the total weight of the outer layer) of the phenolic stabilizer.

First, the base layer and the outer layer are extruded at a extrusion temperature of 230 ° C. and a die temperature of 240 ° C. onto a take-off roll at 90 ° C., and then before winding at a temperature of 150 to 16 ° C.
The film was stretched in the longitudinal direction at 0 ° C (longitudinal stretching ratio: 2.0), and then stretched in the transverse direction at a temperature of 170 to 175 ° C (horizontal stretching ratio: 3.2). The films produced in this way had the properties listed in Table 1.

COMPARATIVE EXAMPLE 12 The concentration of Syloblock 44 in the outer layer was adjusted to 0,0 (based on the total weight of the cyclic olefin copolymers COP ₁ and COP ₂ ).
Films were produced as in Comparative Examples 10 and 11, except that the weight was reduced to 15% by weight. The thickness of the film was 6 μm. Film blending and working conditions
Corresponding to those of Comparative Examples 10 and 11.

The new films (Examples 5 to 7) were obtained from Sylo
It is distinguished by a significantly lower coefficient of sliding friction than can be achieved with block 44. At the same time, Examples 5 to 7 show that the dielectric loss tangent of the Syloblock-containing film is significantly smaller. Test Examples 8-9 also show that equivalently small dielectric loss tangent values can be achieved only for COC films that do not contain antiblocking agents. However, these films cannot be used in practice. The reason is,
This is because they have a strong tendency to stick and have a high coefficient of sliding friction. The films cannot be wound without wrinkling and they stick during unwinding and during all further processing.

[0063]

[Table 1] Ri: Inside the film Ro: Outside the film

The values for the raw materials and the films were obtained using the following measuring methods: Viscosity number J The viscosity number is a measure of the molar mass and at 135 ° C.
DIN 53 in a 0.1% decahydronaphthalene solution
728, part 4.

Glass transition temperature The glass transition temperature was determined according to DIN 53 765 from a second heating curve at 20 ° K / min.

Ethylene Content The ethylene content of the COPs was determined by ¹³ C NMR.

[0067] Molecular weight determination (M _W and Mn) molecular weight of these specimens was measured by gel permeation chromatography using polyethylene as the standard.
The eluent was o-dichlorobenzene at a temperature of 135 ° C. Waters 150-C ALC / with Jerdi column system (500 x 10 mm, linear) and RI-64 catheter
GPC was used.

Sliding Friction The sliding friction was measured according to DIN 53375 and was measured on the outside of the film relative to the inside of the film. The coefficient of sliding friction was measured about 23 days after film production (23 ° C. and 50% relative humidity).

Surface Roughness Surface roughness was measured in accordance with DIN 4768 on 0.25 mm and 0.08 mm cut pieces, respectively.

Tear strength and elongation at break The tear strength and the elongation at break were measured according to DIN 53455.

According to DIN 53457 or ASTM 882,
The elastic modulus was measured.

The dielectric loss tangent was determined according to DIN 53483 at 23 ° C. and 50% relative humidity using a measuring voltage of 1 volt and a deposited silver electrode (20 cm ² , layer thickness 150 nm).

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁶ Identification symbol FI B29L 9:00 C08L 23:02 45:00 (72) Inventor Herbert Pfeiffer 55126 Mainz, Thuringer Strasse 26 (72) ) Inventor Wilfried Hatke 65719 Hofheim, Homburger Strasse 9

Claims (24)

[Claims] 1. A film having one or more layers and made of a cyclic olefin polymer and having a base layer and at least one outer layer, wherein the base layer has a glass transition temperature Tg. made substantially of COP, also the outer layer is made essentially of a mixture of cycloolefin polymers, mixtures of the cyclic olefin polymer and at least two kinds of cycloolefin polymers COP ₁ and COP ₂ Wherein the two polymers have different glass transition temperatures Tg ₁ and Tg ₂ by at least 5 ° C., and satisfy Tg ₂ −Tg ₁ ≧ 5 ° C., and simultaneously satisfy the condition Tg ₂ −Tg ≧ 5 ° C. the film. 2. The method according to claim 1, wherein the base layer comprises 90 to 100% by weight of the cyclic olefin polymer or the cyclic olefin polymer mixture.
A film according to claim 1 and further comprising conventional additives if desired. 3. The cyclic olefin polymer of the base layer has the formula I, II, III, IV, V or VI below in each case, based on the total weight of the cyclic olefin polymer: (Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and R
⁸ is the same or different and is a hydrogen atom or C ₁ -C ₃₀
-Is a hydrocarbon group or in the formula two or more groups R ¹
To R ⁸ are bonded in a ring, and the meaning of the same group may be different in different formulas). The film according to any one of claims 1 and 2, wherein the film comprises 10 to 99% by weight. 4. The cyclic olefin polymer of the base layer,
A cyclic olefin copolymer, and based on the total weight of the cyclic olefin copolymer, the following formula VII: 4. The film according to claim 3, comprising at most 45% by weight of polymerized units of at least one type of monocyclic olefin represented by the formula (n is a number of 2 to 10). 5. The cyclic olefin polymer of the base layer,
A cyclic olefin copolymer, and based on the total weight of the cyclic olefin copolymer, the following formula VIII: (R ⁹ , R ¹⁰ , R ¹¹ and R ¹² may be the same or different and represent a hydrogen atom or a C ₁ -C ₁₀ -hydrocarbon group, for example C _1-
C ₈ - alkyl group or a C ₆ -C ₁₄ - film according to claim 3, wherein the polymerized units of an acyclic olefin containing 99 wt% or less represented by the aryl is group). 6. The cyclic olefin polymer of the base layer,
6. The film according to claim 1, which is a norbornene ethylene copolymer or a tetracyclododecene ethylene copolymer having an ethylene content of from 5 to 80% by weight, based on the weight of the copolymer. 7. The cyclic olefin polymer of the base layer,
A glass transition temperature Tg of -20C to 400C, preferably 50 to 200C, and a viscosity number of 0.1 to 200 ml / g, preferably 50 to 150 ml / g (decalin, 135C, DI
N 53728). 8. cyclic olefin polymer COP ₁ and the glass transition temperature Tg ₁ and Tg ₂ of COP ₂ is, differ by at least 5 to 150 ° C., and Tg ₁ <claims 1-7 is Tg ₂ The film according to any one of the above. 9. The cyclic olefin polymer COP ₁ and C ₂ wherein the outer layer is in each case based on the weight of the outer layer.
The OP ₂ comprises 90 to 100 wt%, a and the proportion of COP ₁ is 99.5 to 75 wt%, the proportion of COP ₂ 0.5
The film according to any one of claims 1 to 8, wherein the amount is from 25 to 25% by weight. 10. The cyclic olefin polymer COP
₁ is, in each case based on the total weight of the cyclic olefin polymer, of the following formulas I, II, III, IV, V or VI: (Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and R
⁸ is the same or different and is a hydrogen atom or C ₁ -C ₃₀
-Is a hydrocarbon group or in the formula two or more groups R ¹
To R ⁸ is not coupled to the ring, also in the formula, the polymerization cyclic olefin unit represented by the same meanings of the group may be different in different formulas), from 0.1 to 100 wt%, preferably The film according to any one of claims 1 to 9, comprising 10 to 99% by weight. 11. The cyclic olefin polymer COP
₁ is a cyclic olefin copolymer, and based on the total weight of the cyclic olefin copolymer, the following formula VI
I: The film according to claim 10, comprising 45% by weight or less of a polymerized unit of at least one kind of monocyclic olefin represented by (n is a number of 2 to 10). 12. The cyclic olefin polymer COP
₁ is a cyclic olefin copolymer, and based on the total weight of the cyclic olefin copolymer, the following formula VI
II: (R ⁹ , R ¹⁰ , R ¹¹ and R ¹² may be the same or different and represent a hydrogen atom or a C ₁ -C ₁₀ -hydrocarbon group, for example C _1-
C ₈ - alkyl group or a C ₆ -C ₁₄ - film according to claim 10, wherein the polymerized units of an acyclic olefin containing 99 wt% or less represented by the aryl is group). 13. The cyclic olefin polymer COP
₂ is, in each case based on the total weight of the cyclic olefin polymer, of the following formulas I, II, III, IV, V or VI: (Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and R
⁸ is the same or different and is a hydrogen atom or C ₁ -C ₃₀
-Is a hydrocarbon group or in the formula two or more groups R ¹
To R ⁸ are bonded in a ring, and the meaning of the same group may be different in different formulas). The film according to any one of claims 1 to 12, comprising 10 to 99% by weight. 14. The cyclic olefin polymer COP
₂ is a cyclic olefin copolymer and, based on the total weight of the cyclic olefin copolymer, the following formula VI
I: 14. The film according to claim 13, comprising 45% by weight or less of a polymerized unit of at least one kind of monocyclic olefin represented by (n is a number of 2 to 10). 15. The cyclic olefin polymer COP
₂ is a cyclic olefin copolymer and, based on the total weight of the cyclic olefin copolymer, the following formula VI
II: (R ⁹ , R ¹⁰ , R ¹¹ and R ¹² may be the same or different and represent a hydrogen atom or a C ₁ -C ₁₀ -hydrocarbon group, for example C _1-
C ₈ - alkyl group or a C ₆ -C ₁₄ - film of claim 13, wherein the polymerized units of an acyclic olefin containing 99 wt% or less represented by the aryl is group). 16. The method according to claim 16, wherein the base layer and / or the outer layer comprises a stabilizer,
The film according to any one of claims 1 to 15, further comprising a neutralizing agent and / or an antioxidant. 17. The film according to claim 1, wherein the film has a total thickness of 2 to 50 μm, and the thickness of the outer layer (s) is 0.1 to 5 μm. 18. The film according to claim 1, wherein said film has an outer layer on both sides, preferably the same outer layer. 19. The film according to claim 1, wherein the outer layer (s) does not contain a particulate antioxidant. 20. A step of co-extruding a melt corresponding to each film layer through a flat film die, a step of taking up the co-extruded film by a take-up roll, and a step of stretching the film in a length of 1.1: 1 to 4: 1. Biaxially stretching at a directional stretching ratio and a transverse stretching ratio of 2: 1 to 5: 1, heat setting the biaxially stretched film, corona treating or flame treating the film if desired, and The method for producing a film according to claim 1, comprising a step of winding. 21. The film is stretched at a longitudinal stretching temperature _Tl and a transverse stretching temperature _Tq , wherein said _Tl and Tl
_q is greater than at least 5 ° C. The Tg of the cyclic olefin polymer COP of the base layer, at the same time T _l is at least 3 ° C. lower claim 20 The method according than Tg ₂ cyclic olefin polymer COP ₂ of the outer layer. 22. Use of a film according to any of claims 1 to 13 for producing a metallized film. 23. Use of a film according to any of claims 1 to 13 for producing a film metallized on both sides. 24. A capacitor comprising the film according to any one of claims 1 to 13, 16 and 17.